•7 
exist, lavas and ashes were thrown out, submerging fairly large 
areas of country. So far as researches in the field have been 
carried, the volcanic focii. all seem to be situated along or on the 
northern portion of the area in proximity to what would appear 
to be the shore line of a gradually receeding ocean. The great ex- 
tent of the lava flows and associated cjectmenta seem to imply 
that these centres of eruption must, during Nullagine time, have 
appeared as a remarkable chain of coast volcanoes, but whether 
they arc distributed along lines of orographic movement is one of 
those, as yet unsolved ])roblems of Western Australian geology. 
The occurrence of sandstones, quartzites and other sediments 
interbedded with lava flows, etc., point to the fact that some of 
these volcanic eruptions took i)lace under water, and must have 
been followed by intervals during which sedimentation was carried 
on. 
In the King Leopold Plateau in the far north, these volcanic 
beds occur in great force, and form the highest parts of the country. 
At Mount Hann, a very remarkable cliff-faced mountain 
situated on the highest summit of the plateau, dissected by the 
upper reaches of the King Edward, the Drysdalc and the IVince 
Regent Rivers, the volcanic rocks can be well seen. (Fig. 17). The 
Fig. 17- 
Volcanic Rocks, Mount Hann, Kimberley Division. 
cliffs formed by the faces of the lavas and ashes, rise perpendicularly 
from 100 to flOO feet in height. (Inly one spot on the western face 
of the mountain l)y which an ascent could be made was found. 
From the summit of Mount Hatm, about oOO feet in height, an ex- 
cellent view of the surrounding country could be obtained, and the 
